Autel MS906 Pro vs MK900: when MaxiSys makes sense

The short version

Both tools are full system, bidirectional Autel tablets. Both listings claim 3000+ active tests, both support the newer CAN FD and DoIP protocols, and both can read and clear codes, show live data and freeze frame, and run common service resets. For pulling codes from every module, watching sensor data and commanding a fan, pump or solenoid, they overlap almost completely.

The real split is ECU coding and programming. The MS906 Pro listing advertises advanced ECU coding, online coding and PMI functions shared with Autel's Ultra and Elite II Pro tablets. The MK900BT and MX900 listings do not state ECU coding at all. If you plan to code replacement modules, change vehicle settings or do work that normally needs a dealer tool, that is what the extra money buys. If not, the MK900 class is the better value. Read what ECU coding is if you are not sure whether you need it.

Spec comparison from the listings

The table uses only what the Amazon listings state. Autel sells these tools through several sellers and the bullet points differ a little between them. One MS906 Pro listing says 36+ services and another says 40+, so we show both. The MX900 listing itself claims more services than the MS906 Pro, which tells you the service count is not the difference that matters here.

Note.Listing specs change as sellers update their pages. Check the current listing and Autel's coverage list for your exact vehicle before you buy.

Diagnostics and bidirectional tests: mostly a tie

For everyday diagnosis these tools do the same job. The MK900BT listing describes OE level diagnosis of all systems, including ECM, TCM, PCM, ABS, SRS, BCM, A/C and battery management, with Auto Scan 2.0, live data, freeze frame and 3000+ active tests. The MS906 Pro listing describes the same kind of OE level all system diagnosis with graphing of up to five PIDs at once.

Bidirectional control is the feature that saves the most time on real repairs. Instead of guessing whether a fuel pump, cooling fan, EVAP purge valve or ABS pump works, you command it on from the tablet and watch or listen for a response. Both tools list 3000+ active tests, so neither should hold you back here. Our guide to bidirectional scan tools explains what active tests can and cannot prove.

ECU coding and PMI: the reason the MS906 Pro costs more

The MS906 Pro listing says it shares its ECU functions with Autel's higher end Ultra, MS919 and Elite II Pro tablets. It describes online coding for most mainstream cars, recoding and programming new ECUs, modifying parameters and matching components. PMI refers to Autel's programming and module installation features. These are the jobs that come up when you replace a body module, injector set, transmission control unit or similar part and the car needs the new part configured.

None of that is stated on the MK900BT or MX900 listings. Some service functions such as injector coding appear on the MK900BT list, but full module coding and programming do not. If you rarely replace control modules, you may never miss it. If you work on European cars or do module swaps regularly, coding is often the difference between finishing a job and sending the car to the dealer. Note that coding and programming on many vehicles also need a stable battery supply and, on some makes, an online account.

See scan tools with ECU coding →

Hardware, connection and updates

The MS906 Pro listing gives detailed hardware: an 8-core CPU, Android 10, an 8 inch 1920x1200 screen and 4GB of memory with 128GB of storage. It connects through a Bluetooth VCI. The MK900BT listing highlights its V150 wireless connector with a stated 33 foot Bluetooth range and an 8 inch screen, but does not list the processor or memory. The MX900 listing does not state its screen or connection details.

Both are Autel tablets that rely on software updates for new vehicle coverage. The listings mention subscription renewal in their support notes, which means updates are not free forever. Check the current update terms before you buy, because a year or two of updates is part of the real cost of any tablet. We cover how this works in scan tool updates and subscriptions.

Who should buy which

If you are already leaning toward a mid range Autel, our MK808S vs MK900 comparison covers the step down, and the best Autel scanner guide lists the whole range we cover.

• Buy the MK900BT or MX900 if you want full system, bidirectional diagnostics and 40+ service resets for your own cars or a light repair business, and you do not plan to code or program modules.
• Buy the MS906 Pro if you replace control modules, work on newer European cars that need coding after part swaps, or want the same ECU functions as Autel's higher end tablets without paying for an Ultra.
• Consider neither if you only need to read engine codes and clear the check engine light. A basic scanner does that for far less. See our DIY scanner picks.

Compare Autel scanners →

Frequently asked questions

Is the MS906 Pro worth twice the price of the MK900? Only if you need ECU coding and programming. For reading codes, live data, active tests and service resets, the MK900BT and MX900 listings claim the same 3000+ tests and as many or more service functions.

What is the difference between the MK900, MK900BT and MX900? Autel's listings describe the MK900BT as the Bluetooth V2.0 version of the MK900 and the MX900 as the US version of the MK900 and MK900BT. We compared the MK900BT and MX900 because the plain MK900 is not one of the listings in our guides.

Does the MK900 do ECU coding? Not stated. The MK900BT and MX900 listings mention injector coding as a service function but do not claim the full ECU coding the MS906 Pro listing advertises.

Do both tools work on 2025 and 2026 cars? Both listings claim CAN FD and DoIP support, the newer protocols used by many recent GM, BMW and other vehicles. Coverage still varies by make and model, so check Autel's coverage list for your vehicle.